1. Field of the Invention
The invention relates in general to a liquid crystal display (LCD) and a driving method therefor, and more particularly to a LCD with improved motion image quality and a driving method therefor.
2. Description of the Related Art
FIG. 1 is a partially schematic illustration showing a conventional amorphous silicon thin film transistor LCD. Referring to FIG. 1, the LCD has a plurality of pixels P arranged in an array, a plurality of scan lines S and a plurality of data lines D orthogonal to the scan lines. Each pixel P has a thin film transistor (TFT) M, a liquid crystal capacitor Clc and a storage capacitor Cst. The liquid crystal capacitor Clc is an equivalent component of a common electrode (not shown) on a top substrate, a pixel electrode (not shown) on a bottom substrate and a liquid crystal layer (not shown) encapsulated between the top substrate and the bottom substrate. The thin film transistor M has a gate coupled to a corresponding scan line, a drain coupled to a corresponding data line, and a source coupled to a corresponding pixel electrode.
The operation state of the LCD will be described by taking the scan lines S(I) and S(I+1), data lines D(J) and D(J+1), and pixels P(I, J) to P(I+1, J+1) as an example. The conventional LCD belongs to a hold type image display mode. When the scan lines S(I) and S(I+1) are sequentially turned on, the voltages corresponding to the pixel data of the pixels P(I, J) to P(I+1, J+1) are respectively inputted to the pixels P(I, J) to P(I+1, J+1) from the data lines D(J) and D(J+1), and these voltages are respectively held by the storage capacitor Cst of each pixel such that the voltage difference between two ends of each liquid crystal capacitor Clc is almost kept at the original voltage for a frame time FT. Therefore, the pixels P(I, J) to P(I+1, J+1) emit light for a frame time FT in order to display the desired frame. The relationship curve between the luminance intensity of a certain pixel and the time while the conventional LCD is displaying an image is shown in FIG. 2.
However, because the conventional LCD belongs to the hold type image display mode, the image dragging phenomenon tends to be caused and the motion image quality is deteriorated when the LCD is displaying the motion images (motion pictures) rapidly. Consequently, it is an important subject in this field to avoid the image dragging phenomenon of the LCD and enhance the motion image quality.